python中字符串的常用拼接

1、 + 号拼接

>>> test1 = "abcd"
>>> test2 = "opqr"
>>> test3 = "xyzh"
>>> test1 + test2
'abcdopqr'
>>> test2 + test3
'opqrxyzh'
>>> test2 + test1 + test3
'opqrabcdxyzh'

2、 % 号拼接

>>> test1 = "the price of apple:"
>>> test2 = 20.55666
>>> "%s is %.1f ！" % (test1,test2)
'the price of apple: is 20.6 ！'
>>> test3 = "mmmm"
>>> test4 = "nnnn"
>>> "test3 + test4 is %s+%s" % (test3,test4)
'test3 + test4 is mmmm+nnnn'

3、join拼接

>>> test1 = ["aaa","ccc","xxx","mmm"]
>>> "_".join(test1)
'aaa_ccc_xxx_mmm'
>>> test1 = ("aaa","ccc","xxx","mmm")
>>> "_".join(test1)
'aaa_ccc_xxx_mmm'